30 lines
796 B
Go
30 lines
796 B
Go
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package beacon
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import (
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"encoding/binary"
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"github.com/minio/blake2b-simd"
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"golang.org/x/xerrors"
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)
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func DrawRandomness(rbase []byte, randomnessType RandomnessType, round uint64, entropy []byte) ([]byte, error) {
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h := blake2b.New256()
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if err := binary.Write(h, binary.BigEndian, int64(randomnessType)); err != nil {
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return nil, xerrors.Errorf("deriving randomness: %v", err)
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}
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VRFDigest := blake2b.Sum256(rbase)
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_, err := h.Write(VRFDigest[:])
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if err != nil {
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return nil, xerrors.Errorf("hashing VRFDigest: %w", err)
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}
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if err := binary.Write(h, binary.BigEndian, round); err != nil {
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return nil, xerrors.Errorf("deriving randomness: %v", err)
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}
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_, err = h.Write(entropy)
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if err != nil {
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return nil, xerrors.Errorf("hashing entropy: %v", err)
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}
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return h.Sum(nil), nil
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}
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